Bucket chain tumbler



J7 ZZ GPZZ 6): j oms C MgL-a/er- 0cm. 4, 1938. T c WHH5LER BUCKET CHAIN TUMBLER Flled. March 30, 1936 Patented Oct. 4, 1938 2,132,198

UNITED STATES PATENT OFFICE BUCKET CHAIN TUMBLER Thomas C. Whisler, Berkeley, Calif., assignor to The American Brake Shoe and Foundry Company, a corporation of Delaware Application March 30, 1936, Serial No. 71,604

4 Claims. (01. 74243) This invention relates to tumblers used for the turning of a single member of each assembly confining and guiding the buckets of endless screw and without friction other than that incichain dredges. These tumblers are conventiondent to the interengaging threads; and the tenally made of two. identical flanged members sion applied to the several assembly screws being 5 mounted in apposition upon a shaft so that while sufficiently appreciable by the experienced oper- 6 their flanges confine the chain of buckets against ative to enable him to impart approximately unilateral displacement in opposite directions, their form tension to all of the circumferentially distread portions together provide the bearing surtributed screws. A collateral object is to develop face over which the buckets run. substantial support for the assembly screws at 10 The nature of the stresses imposed by the points axially removed from the outer web in 10 buckets passing over tumblers of this kind is which the screws are anchored. such that the metal of the treads as heretofore Accordingly, other features of the present indesigned, and especially when made of manganese vention proceed upon the principle of constructsteel, flows in response to these stresses in a ing each assembly screw of three parts, namely,

direction that results in circumferential enlargetWo anchoring parts which are seated non-notat- 15 ment of the tread, particularly near the unreably in the respective outer radial supporting strained portion of the tread or the portion which webs, and a third part having right and left is remote from the radial web through which the threaded connections with the respective anchortread is mounted upon the hub. The result is ing parts, and feeding both the latter simultathat the treads become distorted, the confining neously inward or outward according to direction 20 flanges are gradually thrown out of their plane, of rotation of the rotatable part and having all and the wearing life of the tumbler is unduly of the rotatable parts of the assembly screws shortened, accessible for adjustment near a medial plane One object of the present invention is to proof the assembled tumbler; the assembly screws long the usefulness of tumblers of the kind rebeing not only anchored at their ends in the 25 ferred to by preventing the circumferential enrespective outer radial webs of the tumbler memlargement and consequent distortion of their bers, but being made to pass through openings in treads; and to this end, one feature of the inthe growth-resisting webs, and the latter, while vention proceeds upon the principle of designing leaving the rotatable portions of the screws free each of the two members which make up the to turn, having the confines of their openings 30 tumbl r with not only th conventional hub, sufficiently near to the assembly screws to limit radial supporting web and barrel-like tread porfie and prevent breaking of e C eWS under tion extending in the direction of the axis of pressu e o a Stone Other Object that y the tumbler from its said supporting web, but come trapped between the bucket chain and the with an adjunctive web or flange-which I shall tumbler. 35

herein term growth resisting webextending In the accompanying drawinginwardly from that portion of the tread which Figure 1 is an axial View of the new tumbler is remote from its conventional supporting web, together with dotted line indication of a portion is circumferentially continuous and co-extensive of the endless bucket chain with which it is to be 40 with the tread to which it is united, and extends used. 40

radially inward a distance sufficient to resist ra- Figure 2 is a section on the line 2m-2:t of Figdial expansion of the tread and preferably all ure 3, which presents the inner face of one of the way inward to the hub which is sufficiently the two tumbler members in elevation and the elongated axially to receive it and be integrally assembly screws in section.

united to it. Figure 3 is a half axial section of the tumbler 45 Another object of the present invention is to shown in Figures 1 and 2. so construct and dispose the assembly screws em- Figure 4 is a face view of one of the anchoring ployed for drawing axially toward each other the nuts used in Figures 1, 2 and 3. two constituent tumbler members that instead Figure 5 is a section on the line 5-5 of Figure of necessitating individual adjustment of a nut 4; and 50 at each end of each screw, rotatably seated in the Figure 6 is an axial section of the tumbler supporting webs of the tumbler with consequent shown in Figures 1 and 2, but with a modified interference of friction with the o-peratives estiform of three-part assembly screws.

mate of tension being applied, screw adjustment A represents a tumbler adapted to receive and may be attained simultaneously at both ends by guide a bucket chain B; said tumbler being constructed with two identical members A, A2,

connected by assembly screws C consisting of tread members I supported by outer radial webs 2 upon hubs 3 and preferably having confining flanges 2a in line with said outer webs 2. The treads I constituting barrel-like axial extensions from the supporting webs 2, are conventionally left open at their inner ends and, especially when the tumbler is made of rather ductile metal such as manganese steel, yield and flow under the limited surface contact and drag of the straight under sides of the buckets. This causes circumferential growth of the treads with outward displacement of their flanges 2a and other distortions, with the result that the tumbler in many,

instances has to be discarded before it is worn out.

The present invention reinforces the inner ends of the treads I against such distortions by constructing them with adjunctive growth-re sisting webs 4, circumferentially continuous and co-extensive and integral with said treads and extending inwardly therefrom at least a distance ample to prevent circumferential enlargement under the flow of the metal, and preferably integrally united with the hubs 3 Another disadvantage of the open and unsupported inner ends of treads I arises from the lack of protection to the assembly screws C from pieces of rock that sometimes enter into the space between the tumbler members and are pressed against said screws by the traveling buckets. The present invention utilizes the adjunctive inner webs 4 as a means of limiting the flexing of the screws 0 and protecting them against breakage by causing said screws to extend through openings 5 in said inner webs and permitting them to rest against the confines of said openings before the screws can be flexed sufficiently to injure them.

Finally, the present invention affords facility for uniformly tensioning the assembly screws of a tumbler of the kind described; to which end, its screws are constructed of three portions, namely, an intermediate turning portion 6 having right and left hand'threads I, 8, through which they are received in the anchoring members 9 that are non-rotatably seated in the webs 2, 20

According to Figures 1, 2, and 3, the anchoring portions 9 are axially short and in the form of nuts of non-round section seated in webs 2 with their major dimensions presented circumferentially thereof in order-to permit the assem bly screws to be located at a greater distance from the axis of the tumbler; and the intermediate turning portions 6 in this case extend through the openings 5 and serve as the portions that come into bearing and establish support for the screw in the event of encounter with an obstruction in the operation of the dredge.

In Figure 6. the anchoring members 9a, nonrotatably seated in the outer webs 2, are relatively long and are made to carry the right and left threads la, 8a which in this instance cooperate with a central sleeve 611 after the manner of a turnbuckle. In this instance, the anchoring members do constitute the portions that receive support against the inner growth-resisting web 4.

In the construction and disposal of assembly screws in accordance with the present invention, these screws are located parallel to the axis of the tumbler and between the treads I and hubs pendently turn several nuts at the ends of the assembly screws as heretofore, and thus make eight adjustments instead of four, and instead of turning each nut against the large friction incident to seating a rotatable member on manganese steel, the screws of the present invention are adjusted relatively to both web members simultaneously by rotating their middle portions while their anchoring portions remain fixed against rotation, and the friction to be overcome in making these adjustments is only that which is developed between screw threads, so that it becomes comparatively easy for an operative to judge of the'tension put upon each assembly screw and therefore attain uniformity throughout the several connecting points circumferentially distributed around the tumbler.

.I claim:

1. In a bucket chain dredger, a tumbler for confining and guiding the bucket chain, said tumbler comprising a pair of coaxially opposed tumbler members, each individual tumbler member of the pair comprising a hub, a radial supporting web integral with said hub and normally subjected to axially outward tipping forces by the buckets, a circumferentially continuous tread integrally united with and extending axially inward from said supporting web and normally subjected to forces tending to create circumferential enlargement also imposing axially outward displacement of said supporting web, and a circumferentially continuous anti-tipping and growthresisting strutting web extending radially inward from and integral with said tread, remote from said supporting web, and means anchored in the tread supporting webs, tying together the tumbler members and transmitting support from each tumbler member to the supporting web of the other member, against the stresses stated.

2. In a bucket chain dredger, a tumbler for confining and guiding the bucket chain, said tumbler comprising a pair of coaxially opposed tumbler members, each individual tumbler member of the pair comprising a hub, a radial supporting web integral with said hub and normally subjected to axially outward tipping forces by the buckets, a circumferentially continuous tread integrally united withand extending axially inward from said supporting web and normally subjected to forces tending to create circumbler comprising a pair of coaxially opposed suitiab-ly united tumbler members, each individual tumbler member of the pair comprising a hub, a radial supporting web integral with said hub and normally subjected to axially outward tipping fcrces by the buckets. a circumferentially continuous tread integrally united with and extending axially inward from said supporting web and normally subjected to forces tending to create circumferential enlargement also imposing axially outward displacement of said supporting continuous tread integrally united with and extending axially inward from said supporting web and normally subjected to forces tending to create circumferential enlargement also imposing axially outward displacement of said supporting web, and a circumferentially continuous antitipping and growth-resisting strutting web extending radially inward from and integral with said tread, remote from said supporting web,

said last-named web extending to and being in- 10 tegrally connected with said hub.

THOMAS C. WHISLER. 

